Dataplot Vol 2 Vol 1

# DIFFERENCE OF GEOMETRIC MEAN

Name:
DIFFERENCE OF GEOMETRIC MEAN (LET)
Type:
Let Subcommand
Purpose:
Compute the difference between the geometric means for two response variables.
Description
The geometric mean is defined as:

$$\mbox{XGM} = (\prod_{i=1}^{n}{X_i})^{1/n}$$

For the differeence of geometric means, the geometric mean is computed for each of two samples then their difference is taken.

Syntax:
LET <par> = DIFFERENCE OF GEOMETRIC MEAN <y1> <y2>                         <SUBSET/EXCEPT/FOR qualification>
where <y1> is the first response variable;
<y2> is the first response variable;
<par> is a parameter where the computed difference of the geometric means is stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
LET A = DIFFERENCE OF GEOMETRIC MEAN Y1 Y2
LET A = DIFFERENCE OF GEOMETRIC MEAN Y1 Y2 SUBSET X > 1
Note:
Dataplot statistics can be used in a number of commands. For details, enter

Default:
None
Synonyms:
None
Related Commands:
 GEOMETRIC MEAN = Compute the geometric mean. DIFFERENCE OF MEAN = Compute the difference of means. DIFFERENCE OF HARMONIC MEAN = Compute the difference of harmonic means. DIFFERENCE OF MEDIAN = Compute the difference of medians. DIFFERENCE OF TRIMMED MEAN = Compute the difference of trimmed means. DIFFERENCE OF MIDMEAN = Compute the difference of midmeans. DIFFERENCE OF BIWEIGHT LOCATION = Compute the difference of biweight locations. STATISTICS PLOT = Generate a statistic versus subset plot. BOOTSTRAP PLOT = Generate a bootstrap plot. TABULATE = Perform a tabulation for a specified statistic.
Applications:
Data Analysis
Implementation Date:
2003/03
Program:
SKIP 25
READ IRIS.DAT Y1 TO Y4 X
.
LET A = DIFFERENCE OF GEOMETRIC MEAN Y1 Y2
TABULATE DIFFERENCE OF GEOMETRIC MEAN Y1 Y2 X
.
XTIC OFFSET 0.2 0.2
X1LABEL GROUP ID
Y1LABEL DIFFERENCE OF GEOMETRIC MEANS
CHAR X
LINE BLANK
DIFFERENCE OF GEOMETRIC MEAN PLOT Y1 Y2 X
CHAR X ALL
LINE BLANK ALL
BOOTSTRAP DIFFERENCE OF GEOMETRIC MEAN PLOT Y1 Y2 X

Dataplot generates the following output.
       **************************************************
**  LET A = DIFFERENCE OF GEOMETRIC MEAN Y1 Y2  **
**************************************************

THE COMPUTED VALUE OF THE CONSTANT A             =  0.27591226E+01

*****************************************************
**  TABULATE DIFFERENCE OF GEOMETRIC MEAN Y1 Y2 X  **
*****************************************************

*    Y1       AND Y2
X           *    DIFFERENCE OF GEOMETRIC MEANS
**********************************************
1.00000     *     1.58676
2.00000     *     3.16211
3.00000     *     3.60078

GROUP-ID AND STATISTIC WRITTEN TO FILE DPST1F.DAT



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Date created: 03/21/2003
Last updated: 11/09/2015